No, 278 is not a prime number. It is a composite number: it is even, so it is divisible by 2.
278 has divisors other than 1 and itself. The smallest is 2: 278 ÷ 2 = 139.
Prime factorization: 278 = 2 × 139.
| Number | Prime? |
|---|---|
| 274 | No, 2 × 137 |
| 275 | No, 5 × 5 × 11 |
| 276 | No, 2 × 2 × 3 × 23 |
| 277 | Yes |
| 279 | No, 3 × 3 × 31 |
| 280 | No, 2 × 2 × 2 × 5 × 7 |
| 281 | Yes |
| 282 | No, 2 × 3 × 47 |
Another number? Use the prime number checker for any value, or see the list of prime numbers.